One day after President Obama submitted his budget request for fiscal 2012 to Capitol Hill, congressional Republicans assailed the document as too weak on spending. But they also signaled an openness to working with Democrats to solve the nation's financial problems.

The mixed message reflects uncertainty among resurgent Republicans about how best to address the concerns of voters - and satisfy the demands of restless freshman members of their own party.

Some Republicans, particularly those in the House, want to force an immediate showdown with Democrats: GOP leaders have included sharp cuts to federal agencies in a must-pass spending measure that would keep the government open through September. Other Republicans, including many longtime senators, want to seize the moment to join Democrats in overhauling politically sensitive programs such as Social Security and Medicare, the biggest drivers of future spending.

The confusion was evident Tuesday in congressional budget hearings, where GOP lawmakers grilling White House budget director Jacob J. Lew veered between criticizing Obama as not addressing the looming crisis in entitlement programs and asking what they could do to help.

"People on this panel here, at least on this side of the aisle, invite the dialogue, encourage it, with the White House on this," said Rep. Todd C. Young (R-Ind.), a Marine veteran who sits on the House Budget Committee. "What might I do, as a freshman member of Congress, to create the political space where the president can step up and take a leadership role in these matters?"

At the White House, Obama played down his much-criticized $3.7 trillion spending plan in his first news conference of the year, calling it the initial step in what promises to be a lengthy negotiation over the government's fiscal future. He again invited Republicans to join him in seeking bipartisan solutions for handling the skyrocketing costs of health care and an aging population.

"The first step in this budget is to make sure that we're stabilizing the current situation," the president said of his blueprint, which would reduce record budget deficits over the next decade and stabilize government borrowing. "The second step is going to be to make sure that we're taking on some of these long-term drivers."

For now, at least, those steps are tangled in a single battle that will affect spending levels this year, next year and beyond. Untangling the process, Obama said, will require both parties to engage in the kind of trust-building that produced legislative successes in December, including an extension of dozens of expiring tax breaks, repeal of the "don't ask, don't tell" ban on gay men and lesbians serving openly in the military, and the New START nuclear pact.

"This is not a matter of 'You go first' or 'I go first,' " Obama said. "This is a matter of everybody having a serious conversation about where we want to go and then ultimately getting in that boat at the same time so it doesn't tip over."

In the Senate, where the December deals were forged, Republicans were receptive to that message. But they argued that Obama missed a chance in his budget to send a signal that costly entitlement programs are on the table.

"Entitlement reform will not be done except on a bipartisan basis with presidential leadership," Senate Minority Leader Mitch McConnell (R-Ky.) told reporters. "I've been inviting the president to have that conversation since he took office two years ago," he added. "It doesn't have to be in public. We all understand there are some limitations to negotiating significant agreements in public."